Lubricant



Patented July 25, 1939 UNITED STATES PATENT OFFICE LUBRICANT No Drawing. Application June 2, 1936, Serial No. 83,075

21 Claims.

This invention relates to lubricating oils and more particularly to a process for improving the viscosity-temperature relationships of lubricating oils.

The use of polymerized hydrocarbons and their hydrogenation products as well as hydrogenated rubber has been proposed. Patent 1,998,350 issued to Carl Wulff covers the addition of viscosity improving agents to lubricating oils, which agents are selected from hydrocarbons having a molecular weight of more than 800, and from groups consisting of polymerization products of unsaturated hydrocarbons capable of forming polymeric homologous series together with their products obtained by hydrogenation or isomerization. Polymers mentioned are those obtained from styrene, isobutylene, butadiene, hydrogenated rubber, cyclorubber, and hydrogenated cyclorubber. British Patent 379,717 is similar to the above U. S. patent. French Patent 760,861 delivr December 27, 1933, discloses the hydrogenation of lubricating oils and the addition to these oils of various polymeric agents free of oxygen for example hydrogenated rubber. French Patent 762,289 delivr January 18, 1934, covers the addition to lubricating oils of polymeric hydrocarbon substances either by direct addition of the polymer or by adding the unsaturated hydrocarbon to the oils, followed by polymerization. British Patent 422,471 accepted January 7, 1935, covers a process for the production of high quality lubricating oils which consists in treating the oils with liquefied hydrocarbons which are gaseous at ordinary temperatures, such as propane, to remove asphaltic material, followed by the addition of a synthetic hydrocarbon product of high molecular weight, soluble in the oil.

When the processes of the above patents are followed, oils of improved viscosity are obtained but the agents employed have a pronounced thickening effect on the oils and act as viscosity improving agents solely by their ability to maintain viscosity at high temperatures. These materials must be applied to 'oils having an initial viscosity very materially lower than that of the desired product.

An object of the present invention is to improve upon the processes of the prior art as exemplified by the above patents. A further object is the production of improved lubricating oils by a process which will avoid a thickening action and permit the use of either initially high or low viscosity oils. A further object is to produce medium heavy lubricating oils Jf high viswill usually not exceed 50 per cent.

cosity index from heavy oils. Still further objects are to provide new compositions of matter and to advance the art. Still other objects will appear hereinafter. I

The aboveobjects may be accomplished in ac- 5 cordance with my invention which comprises adding to a lubricating oil the combination of 'an oil soluble polymerized aliphatic hydrocarbon product having a molecular weight of at least 800 and a material'capable of dissociating l0 aggregates of oil molecules which form in mineral oils as the temperature is lowered. The polymeric substances may be any of such substances disclosed in the patents hereinbefore refrred to. However, I preferably employ hydrol5 genated rubber or polymeric products derived from cracked light ends of refinery gasoline, which products do not decompose appreciably on heating to a temperature of 200 C. for a period of 5 minutes.

I have found that materials capable of dissociating aggregates of oil molecules are hydrogenated condensed ring compounds. Preferably, these compounds should be devoid of acidic substituents. Also, the substituents, if any, should be devoid of elements other than carbon, hydrogen, oxygen and nitrogen. The most effective compounds appear to be hydrocarbon compounds consisting solely of carbon and hydrogen. Of these, decahydronaphthalene appears to be the most satisfactory although other suitable compounds are tetrahydronaphthalene, hydrogenated anthracene, beta-naphthanone, hydrogenated alpha-naphthylamine, and the like.

The quantities of my compounds added to the oil will be determined by the characteristics desired in the finished product and by the molecular weight of the polymeric agent. In general, however, the quantity of polymeric agent will not exceed 30% and preferably will lie between 0.2 per cent and 10 per cent by weight of the oil. In practice the quantity will generally range from about 0.3 per cent to about 5 per cent by weight of the oil. The quantity of the dissociating agent I preferably use from about 5 to about 20 per cent by weight of the oil. In practice, the amount of dissociating agent will range from about 10 to about 20 per cent.

Preferably, the polymeric substance is dis- 50 persed in the dissociating agent and the resulting mixture is stirred into the oil while heating to 150 C. until complete homogeneity is obtained.

In order to more fully illustrate my invention, the preferred modes of carrying the same into eii'ect and the advantageous results to be obtained thereby, solutions'were prepared as described in the preceding paragraph. The improvement in the quality of the oil was measured by determining the viscosity at 100F. and 210 F. and then calculating the'viscosity index according to the method described by Dean and vDavis in Chem. and Met. Eng. 36, 618 (1929).

This index serves as a measure of the flatness of the viscosity-temperature curve of, an oil. with increasing values of the index, viscosity- I Following the same procedure with another oil, the results in Table II were obtained.

Table. II

Bay bolt Untlversal Vim 7 Material addedtooil I i? .1oo r. 210 F.

. Second; Second: None 329 54. 2 97 0.37 polymerined cracked M.-- 411 61 108 0. polymerized cracked gases-F 10% demhydronaptbalene mo 55 1 It will beinoted that in each case a distinct improvementzwas obtained in'the viscosity index of the oil the. use of the decahydronaphthalane-polymer combination over the use of the polymer alone.*- It will also be noted that the viscosity at both 1 00 .and 210 F. is aflected to a very much smaller extent by the use oi the :umblnation than by the use of the polymer it- The materials of invention may be added separately to the oil, as hereinbefore described,

or may be mixed with each other and subse-,

quently added to the oil. In "certain cases the desiredefl'ect may be secured by dissolving the raw materials inthe oil followed by polymerization or by hydrogenation. For example, rubber and naphthalene could be dissolved in the oil and the mixture hydrogenated to produce an effect equivalent to the direct addition of corresponding amounts'of hydrogenated rubber and decahydronaphthalene Isobutylene or 'butadiene or other mixtures of oleflnes may be dissolved in the oil together with naphthalene and the mixture polymerized and then hydrogenated. Various other changes and modifications may be made'in my invention without departing from the spirit thereof. Accordingly, my invention is to be limited solelyby the appended claims construed as broadly as is permissible in view of the prior art.

I claim: l. A composition of matter comprising a lubrieating all having incorporated therein about 0.2

hehydrogenated oil.

to about 30% of a polymerized aliphatic hydrocarbon'product having a molecular weight of at least 800 and from about 5 to about 50% of a hydrogenated condensed ring compound devoid .of acidic substituents.

' 2. A composition of matter comprising a lubricating oil having incorporated therein about 0.2 to about 30% of a polymerized aliphatic hydrocarbon product having a molecular weight of at least 800 and from about '5 to about 50% of a hydrogenated condensed ring compound devoid of acidic substituentsand substituents containing elements other than carbon, hydrogen, oxygen and nitrogen.

3. A composition-oi matter comprising a lubrieating oil having incorporated therein about 0.2 to about 30% of a. polymerized alpihatic hydrocarbon product having a molecular weight oi! at least 800 and from about 5 to about 50% of a 20 hydrogenated condensed ring compound consisting of carbon and hydrogen.

4. A composition of matter comprising a lubrieating oil having incorporated therein about 0.2

to about 30% of a polymerized aliphatichydrocarbon product having a molecular weight of at least 800 and. from about 5 to about 50% of an unsubstituted hydrogenated condensed ring compound.

5. A composition of matter comprising a lu-- bricating oil having incorporated therein about 0.2 to about 30%-of a polymerized aliphatic hydrocarbon product having a molecular weight of at least'800 and from about 5 to about 50% of a hydrogenated naphthalene.

6. A composition 01' matter comprising a m bricating oil having incorporated therein about 0.2 to about 30% of hydrogenated rubber and from about 5 to about 50% of a hydrogenated condensed'ring compound devoid of acidic substituents. "40

'7. A composition of matter comprising a lubricating 011 having incorporated thereinabout 0.2 to about 30% of hydrogenated rubber and from about 5 to about of a hydrogenated condensed ring compound consisting 01' carbon '45 and hydrogen.

8. A composition of matter comprising a lubricating oil having incorporated therein about 0.2 to about 30% of hydrogenated rubber and from about 5 to about 50% of a hydrogenatedo naphthalene.

9. A composition of matter comprising a hydrocarbon oil having incorporated therein about 0.2 to about 30% of a polymerized aliphatic hydrocarbon product having a molecular weight oi.' at

least 800 and, from about 5 to about 50% of a hydrogenated condensed ring compound devoid oi acidic substituents.

l0.A composition of matter comprising a hydrocarbon oil having incorporated therein about so 0.2 to about 30% of a polymerized aliphatic hydrocarbon product having a molecular weight of at least 800 and from about 5 to about 50% of a hydrogenated condensed ring compound consisting of carbon and hydrogen. 5 I

11. A composition of. matter comprising a hydrocarbon oil having incorporated therein about 0.2 to about 30%; of a polymerized aliphatic hydrocarbon product having a molecular-weight of at least 800 and from about 5'to about 50% of a hydrogenated naphthalene.

12. A composition of matter comprising a hydrocarbon oil having incorporated therein about 0.2 to about 30% of hydrogenated rubber and from about 5 to about 50% or a hydrogenated 1| aroma;

condensed ring compound consisting of carbon and hydrogen.

13. A composition of matter comprising a hydrocarbon oil having incorporated therein about 0.2 to about of hydrogenated rubber and from about 5 to about of a hydrogenated naphthalene.

14. A composition of matter comprising alubricating oil having incorporated therein about 0.2 to about 30% of a polymerized aliphatic hydrocarbon product having a molecular weight of at least 800 and from about 5 to about 50% of decahydronaphthalene.

15. A composition of matter comprising a hydrocarbon oil having incorporated therein about 0.2 to about 30% of a hydrogenated rubber and from about 5 to about 50% of decahydronaphthalene.

16. A composition of matter comprising a lubricating oil having incorporated therein about 0.2 to about 30% of polymerized cracked gases having a molecular weight of at least 800 and from about 5 to about 50% of a hydrogenated condensed ring compound devoid of acidic substituents.

17. A composition of matter comprising a hydrocarbon oil having incorporated therein about 0.2 to about 30% of polymerized cracked gases having a molecular weight of at least 800 and from about 5 to about 50% of a hydrogenated condensed ring compound deviod of acidic substituents.

18. A composition of matter comprising a hydrocarbon oil having incorporated therein about 0.2 to about 30% of polymerized cracked gases having a molecular weight of at least 800 and from about 5 to about 50% of a hydrogenated condensed ring compound consisting of carbon and hydrogen.

19. A composition of matter comprising a hydrocarbon oil having incorporated therein about 0.2 to about 30% of polymerized cracked gases having a molecular weight of at least 800 and from about 5 to about 50% of a hydrogenated naphthalene.

20. A composition of matter comprising a lubricating oil having incorporated therein about 0.2 to about 30% of polymerized cracked gases having a molecular weight of at least 800 and from about 5 to about 50% of decahydronaphthalene.

21. A composition of matter comprising a hydrocarbon oil having incorporated therein about 0.2 to about 30% of polymerized cracked gases having a molecular weight of at least 800 and from about 5 to about 50% of decahydronaphthalene.

MELVIN A. DIETRICH. 

